/Engine/Source/Runtime/Engine/Classes/Animation/MirrorDataTable.h
Create Mirror Bone Indices for the provided BoneContainer. The CompactBonePoseMirrorBones provides an index map which can be used to mirror at runtime
static void FillCompactPoseMirrorBones ( const [FBoneContainer](API\Runtime\Engine\FBoneContainer) & BoneContainer, const TCustomBoneIndexArray< [FSkeletonPoseBoneIndex](API\Runtime\AnimationCore\FSkeletonPoseBoneIndex), [FSkeletonPoseBoneIndex](API\Runtime\AnimationCore\FSkeletonPoseBoneIndex) > & MirrorBoneIndexes, TCustomBoneIndexArray< [FCompactPoseBoneIndex](API\Runtime\AnimationCore\FCompactPoseBoneIndex), [FCompactPoseBoneIndex](API\Runtime\AnimationCore\FCompactPoseBoneIndex) > & OutCompactPoseMirrorBones )